﻿<p><em>IfcCircleHollowProfileDef</em>
defines a section profile that provides the defining parameters of a
circular hollow section (tube) to be used by the swept area solid. Its
parameters and orientation relative to the
position coordinate system are according to the following
illustration.The centre of the position coordinate system is in the
profile's centre of the bounding box (for symmetric profiles identical
with the centre of gravity).</p>

<blockquote class="history">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<p>Figure 2 illustrates parameters of the circular hollow profile definition. The parameterized profile defines its own position coordinate system. The underlying coordinate system is defined by the swept area solid that uses the profile definition. It is the xy plane of:</p>
      <ul>
        <li><em>IfcSweptAreaSolid.Position</em></li>
      </ul>
<p>By using offsets of the position location, the parameterized profile can be positioned centric (using x,y offsets = 0.), or at any position relative to the profile. Explicit coordinate offsets are used to define cardinal points (for example, upper-left bound). The parameterized profile is defined by a set of parameter attributes.</p>

<table>
<tr><td><img src="../../../figures/ifccirclehollowprofiledef.gif" alt="CHS-shape profile" border="0" height="300" width="400"></td></tr>
<tr><td><p class="figure">Figure 2 &mdash; Circle hollow profile</p></td></tr>
</table>